The invention disclosed and claimed herein pertains to a method and apparatus for optimizing data transfer between a general-purpose terminal or user equipment (UE) and any one of several different access networks. More particularly, the invention pertains to method and apparatus of the above type wherein the UE and respective access networks are to be used in connection with mobile or wireless computing. Even more particularly, the invention pertains to method and apparatus of the above type wherein the general-purpose UE may be readily and automatically configured to use codecs and quality of service (QoS) definitions supported by any of the access networks selected for use, thereby optimizing application performance and resource utilization.
It is now possible to foresee a scenario wherein users will be able to employ general-purpose UEs to connect to the Internet through any one of a number of different access network types, wherein these networks are very different from one another in terms of delay, jitter, bandwidth, bit errors and the like. For example, the emerging GPRS (General Packet Radio Service) networks exhibit rather long delays and low bandwidths, whereas future generation UMTS (Universal Mobile Telecommunication System) and WLAN (Wireless Local Area Network) exhibit lower delays and much higher bandwidths.
There is currently a great effort from vendors of cellular networks such as UMTS to optimize the utilization of the wireless link, in order to significantly increase cost efficiency for the network operator. To this end, vendors standardize Quality of Service (QoS) classes to suit particular codecs and media formats selected for use over these networks. The Quality of Service classes are defined in such a way to not only give optimum media quality delivery, but also to make the most efficient use of the involved radio resources. However, this optimization effort places a limitation on the use of general-purpose wireless UEs, that is, UEs not specifically built for use with a specific network. This limitation is caused by a mismatch of codecs and reservation methods/capabilities which can occur between the general-purpose UE and a particular one of the specific access networks. The UE of relevance is here, both when the UE functionality is vertically integrated into one unit such as a cellular phone, but also when the UE is an aggregate of several units, e.g., a cellular phone connected to a laptop or PDA, or even a Personal Area Network formed by a number of end user devices (such as cell phones, digital cameras and PDA's).
Moreover, it is likely that different access networks will implement different methods for reserving resources and different service definitions or classes. Thus, UEs could require the capability to support different methods and configurations, for a number of different access networks, and to be able to distinguish between all the different network types. It could also become necessary for users to be able to manually configure UEs with the local service definitions and methods of respective different networks. For example, a user having a subscription with carrier A to access the UMTS network might find that when roaming into the UMTS network of carrier B, the service classes are quite different and therefore the user's applications perform differently.
It is virtually impossible for application developers to predict Quality of Service definitions for every access network which may be used with a general-purpose UE. Therefore, there will frequently be a mismatch between the Quality of Service desired by a user and the services offered by a particular selected network.
Finally, at present different networks have quite different service classes with locally well-defined resource reservation mechanisms, but there is no existing method of easily switching between different mechanisms and service definitions. None of the current solutions is able to optimize the data transfer using the native or standardized codecs and formats of the respective access networks, for a general-purpose UE. Such solutions either rely on the UEs being built specifically for a certain access type, or they use formats that exhibit sub-optimum resource utilization. In addition, these solutions may require the UEs to pre-install suitable codecs for all possible access networks and media types. Moreover, there is no existing method for transparently providing the coupling codecs-resource reservation mechanisms and/or classes to UEs, in order to overcome the problem of shifting or changing definitions in different access networks.